1. Field of the Invention
The present invention relates to an organic light emitting display device.
2. Description of Related Art
Recently, various types of flat panel display devices have been developed which have reduced weight and volume as compared to cathode ray tubes. The flat panel display devices include liquid crystal display devices, field emission display devices, plasma display devices, organic light emitting display devices, and others.
Among the flat panel display devices, organic light emitting display devices have excellent color reproducibility, slimness, and other advantages. Accordingly, it is widely used in a variety of applications such as PDAs and MP3 players, in addition to mobile phones.
An organic light emitting display device displays images using organic light emitting diodes (OLEDs) in which luminance is determined corresponding to an amount of current input to the OLEDs.
An organic light emitting diode includes an anode electrode, a cathode electrode, and a red, green or blue light emitting layer interposed between the anode and cathode electrodes. In the organic light emitting diode, luminance of light is determined depending on an amount of current flowing between the anode and cathode electrodes.
Red, green and blue light emitting layers are formed of different materials. Thus, although the same amount of current is applied to the red, green and blue light emitting layers, their light emitting efficiencies are different. Therefore, separate gammas are applied to the red, green and blue light emitting layers.
In a conventional organic light emitting display device, a data driver is generally positioned at a side of a panel, i.e., along an upper or lower portion of the panel. Here, the data driver applies data signals to respective pixels provided in the panel. When the data driver is positioned at a lower portion of the panel, it is assumed that the data driver has 33 pins, and the 33 pins are sequentially numbered from left to right. Then, red, green and blue data are repeatedly output sequentially from a first pin to a thirty-third pin. When the data driver is positioned at an upper portion of the panel, the order of pin numbers is changed, and red, green and blue data are repeatedly output sequentially from the thirty-third pin to the first pin.
At this time, separate gammas are applied to the respective pins. When the data driving unit is positioned at the lower portion of the panel, a red gamma is applied to a first pin, a fourth pin, a seventh pin, . . . , a green gamma is applied to a second pin, a fifth pin, an eighth pin, . . . , and a blue gamma is applied to a third pin, a sixth pin, a ninth pin, . . . . That is, gammas suitable for the respective colors are applied to data output through respective lines.
However, when the same data driver is positioned at an upper portion of the panel, the order of the pin numbers is changed. Therefore, colors of data do not correspond to the gammas. That is, the red gamma is applied to the first pin, the fourth pin, the seventh pin, . . . , the green gamma is applied to the second pin, the fifth pin, the eighth pin, . . . , and the blue gamma is applied to the third pin, the sixth pin, the ninth pin, . . . . However, blue data are output through the first pin, the fourth pin, the seventh pin, . . . , green data are output through the second pin, the fifth pin, the eighth pin, . . . , and red data are output through the third pin, the sixth pin, the ninth pin, . . . . Therefore, when this data driver is positioned at the upper portion of the panel, luminance and/or white balance is compromised. Accordingly, the data driver is designed differently depending on positions of the panel in which the data driver is mounted. For this reason, manufacturing cost is increased.